It might be possible to consider the Voith Schneider propeller as a fully-submerged feathering paddlewheel.
Oh yes, indeed. That's an idea which has been haunting me for some time, but as usual, one life is too short for all these silly projects.
This is what my boys used to have as a wind-up toy in their bathtup. This one doesn't dive, of course, but simply paddles around on the surface:

Starting from that design, you could replace the two wheels with two vertical Fowler wheels or Voith-Schneider props. By means of their (individually) fully vectored thrust, the vessel would have comple 3D-steerability. Up and down, forward and back, spinning about the vertical axis, ...
In fact, this would be dynamic diving, but like static diving without the need of ground speed. No need of ballast tanks, movable fins or rudders, or whatsoever!
Here's a little 2-minute-sketch I just made to show how such a thing might look like:

Moritz